sv-parser/src/parser/behavioral_statements/conditional_statements.rs
2019-07-09 18:08:24 +09:00

103 lines
2.7 KiB
Rust

use crate::parser::*;
use nom::branch::*;
use nom::combinator::*;
use nom::multi::*;
use nom::sequence::*;
use nom::IResult;
// -----------------------------------------------------------------------------
#[derive(Debug)]
pub struct ConditionalStatement<'a> {
pub nodes: (
Option<UniquePriority>,
ConditionalStatementBody<'a>,
Vec<ConditionalStatementBody<'a>>,
Option<StatementOrNull<'a>>,
),
}
#[derive(Debug)]
pub enum UniquePriority {
Unique,
Unique0,
Priority,
}
#[derive(Debug)]
pub struct ConditionalStatementBody<'a> {
pub nodes: (CondPredicate<'a>, StatementOrNull<'a>),
}
#[derive(Debug)]
pub struct CondPredicate<'a> {
pub nodes: (Vec<ExpressionOrCondPattern<'a>>,),
}
#[derive(Debug)]
pub enum ExpressionOrCondPattern<'a> {
Expression(Expression<'a>),
CondPattern(CondPattern<'a>),
}
#[derive(Debug)]
pub struct CondPattern<'a> {
pub nodes: (Expression<'a>, Pattern<'a>),
}
// -----------------------------------------------------------------------------
pub fn conditional_statement(s: Span) -> IResult<Span, ConditionalStatement> {
let (s, x) = opt(unique_priority)(s)?;
let (s, _) = symbol("if")(s)?;
let (s, y) = conditional_statement_body(s)?;
let (s, z) = many0(preceded(
pair(symbol("else"), symbol("if")),
conditional_statement_body,
))(s)?;
let (s, v) = opt(preceded(symbol("else"), statement_or_null))(s)?;
Ok((
s,
ConditionalStatement {
nodes: (x, y, z, v),
},
))
}
pub fn conditional_statement_body(s: Span) -> IResult<Span, ConditionalStatementBody> {
let (s, _) = symbol("(")(s)?;
let (s, x) = cond_predicate(s)?;
let (s, _) = symbol(")")(s)?;
let (s, y) = statement_or_null(s)?;
Ok((s, ConditionalStatementBody { nodes: (x, y) }))
}
pub fn unique_priority(s: Span) -> IResult<Span, UniquePriority> {
alt((
map(symbol("unique0"), |_| UniquePriority::Unique0),
map(symbol("unique"), |_| UniquePriority::Unique),
map(symbol("priority"), |_| UniquePriority::Priority),
))(s)
}
pub fn cond_predicate(s: Span) -> IResult<Span, CondPredicate> {
let (s, x) = separated_nonempty_list(symbol("&&&"), expression_or_cond_pattern)(s)?;
Ok((s, CondPredicate { nodes: (x,) }))
}
pub fn expression_or_cond_pattern(s: Span) -> IResult<Span, ExpressionOrCondPattern> {
alt((
map(expression, |x| ExpressionOrCondPattern::Expression(x)),
map(cond_pattern, |x| ExpressionOrCondPattern::CondPattern(x)),
))(s)
}
pub fn cond_pattern(s: Span) -> IResult<Span, CondPattern> {
let (s, x) = expression(s)?;
let (s, _) = symbol("matches")(s)?;
let (s, y) = pattern(s)?;
Ok((s, CondPattern { nodes: (x, y) }))
}